A new study that examined participants’ cognitive abilities after they took a nap demonstrates that a simple nap may help make you “smarter.”

The research, conducted at the University of California at Berkeley, examined the brain boosting effects of a nap on 39 healthy adults. Half the subjects took a 90 minute nap during the day, and then all subjects were administered a set of tests designed to measure cognitive ability.

Those who took the nap outperformed subjects who did not. The people who had a nap improved their ability to learn by 10%, according to the researchers.

“Sleep not only rights the wrong of prolonged wakefulness, but, at a neurocognitive level, it moves you beyond where you were before you took a nap,” noted lead study author Matthew Walker.

Previous research into napping has found competing, sometimes contradictory, results. The latest study suggests that the brain may need sleep to process short-term memories. Perhaps this creates new

In the latest study, participants were given a hard learning task in the morning. Both groups performed similarly on this task. Half the subjects were then given the opportunity to nap for 90 minutes, while the other half stayed awake.

When the cognitive tests were repeated in the afternoon, the people who took a nap outperformed those who didn’t.

When the researchers looked at the participants’ brain electrical activity, they found that the process of cognitive improvement might be happening in a sleep phase between deep sleep and dreaming sleep. Dreaming sleep is also referred to as stage 2 non-rapid eye movement sleep. During this stage, fact-based memories are moved from “temporary storage” in the brain’s hippocampus to another area called the pre-frontal cortex.

“It’s as though the e-mail inbox in your hippocampus is full, and, until you sleep and clear out all those fact e-mails, you’re not going to receive any more mail,” noted lead study author Matthew Walker.

“It’s just going to bounce until you sleep and move it into another folder.”

The results of the study were reported at the AAAS conference in San Diego, CA.